MAX_MATRIX_KEY_NUM
unsigned short keycodes[MAX_MATRIX_KEY_NUM];
#define MAX_KEYPAD_KEYS (MAX_MATRIX_KEY_NUM + MAX_DIRECT_KEY_NUM)
&keypad->keycodes[MAX_MATRIX_KEY_NUM],
code = keypad->keycodes[MAX_MATRIX_KEY_NUM + i];
encoder->key_codes = &keypad->keycodes[MAX_MATRIX_KEY_NUM + i * 2];
int code = MAX_MATRIX_KEY_NUM + 2 * r + idx;
int code = MAX_MATRIX_KEY_NUM + i;